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by raluk 607 days ago
Extra. I am not sure if that is clear from paper, but in example of 1.75 * 2.5 we can represent 1.75 also as (1-0.125) * 2. This gives good aproximations for numbers that are close but less than power of 2. This way abs(a*b) in (1+a)*(1+b) is allways small and strictly less than 0.25.

Another example, if we have for example 1.9 * 1.9 then we need to account for overflow in (0.9 + 0.9) and this seems to induce similar overhead as expressing numbers as (1-0.05)*2 .